Actually, first 30% of travel has a rearward movement. After that it's all forward but viewed at the axle rather than on a graph it looks almost vertical due to the forward/rearward elements being pretty small. Check it out in Linkage software, it's well handy for sounding brainy on t'internet.

I have a Quad II bike and it's flippin' brilliant. As has already been pointed out, the rear suspension extends slightly under pedalling (remember that sag setting is tres important with QUAD II bikes), which would point to a slight rearward movement in the initial part of travel. Both links are of unequal length, which compresses the shock without pulling the axle path too far forwards in the later portion of travel.

It's not uncommon, have a look at the shock placement on Specialized bikes and have a think about how the shock is actuated.